Final answer:
Sentence (5) from the provided text is considered a minor detail as it adds personal sentiment rather than concrete qualifications or experience relevant to the job.
Step-by-step explanation:
The sentence that contains a minor detail is sentence number (5), "This experience has only reinforced my passion for dogs." This statement does not directly relate to the qualifications or experiences that would prepare the candidate for a career in dog walking, but rather serves to express the candidate's emotion and interest in the field.